My Home Ideas

Special Offers

Be the first to know about This Old House contests, sweepstakes, and events and receive special offers and promotions from your favorite home improvement brands. We'll even send you regular reminders to enter our sweepstakes.

If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

Finishing a part of the garage

We would like to create a room in a 3 car garage by walling off about a third of it. What would be the most efficient way to heat and cool the room (about 300 Sq Ft)? We are in Southern California so winters are 40 to 60 degrees and summers are usually in the 90's.

Re: Finishing a part of the garage

You don't say what you'll be using the room for (living space, workshop, etc.) but I'll assume living space. For any air conditioned space, you need a supply and a return for the air to circulate in the room. Be sure the room is insulated where the garage door is. Easy to do. Just put up a stud wall and insulate it as you would any outside wall, with batts and a moisture barrier.

Next, you'll need to run some ducting. If you don't have an airspace above the ceiling (drywall or drop ceiling??), you'll need to build a little soffit (fake ceiling), along one side of the room. In the soffit or above the ceiling, you can run flexible duct work. Try to get the vent over towards the middle of the room so the whole room gets cooled on hot days. Check for a way to get a circulation path for the air.

Someplace in your house is a return air duct which sucks the air from the house, back through the furnace/air handler. If you are going to have a door to the room and it'll be closed part of the time, you'll just have cut the bottom of the door about 1" above the carpet. If it will be open, it may be OK on its own. If you're having heating/cooling problems, you may have to talk with an air conditioning service company who can either suggest a return air method or do it for you.